With large scaling of coal mine production equipment and great improvement of the productivity, the roadway section also gets larger and larger to satisfy the needs of normal production, transportation, ventilation and human passage. However, larger roadway section tends to increase the deformation of the roadway surrounding rock. Especially, since there are a great amount of anchor rods and ropes on the driving face of a large-section coal roadway, the heading face remains unsupported for a long period of time, thus the deformation and wall caving and/or anti-spalling (deformation, damage and collapse of the mine working face and the roadway side wall under mine pressure) problems are serious, frequently leading to safety threat to the working personnel on the driving face. Therefore, prevention and treatment of wall caving and/or anti-spalling of the heading face of the large-section coal roadway are valued increasingly.
Currently, after coal is excavated from a large-section coal roadway in China, the common way is to retain the coal body on the heading face with a heading face protection mesh, set an anchor rod below the protection mesh, press the anchor rod under the protection mesh so that the protection mesh is tightly compacted with the coal wall, and then perform permanent support. After completion of the permanent support construction, the anchor rod pressed below the protection mesh retaining the coal wall on the heading face is pulled out. The method has complex steps, the roadway driving speed is slow, the protection mesh is pressed by a single anchor rod with small protection range and poor effect, and accidents in which loose coal and rock blocks fall down and hurt persons occur frequently.